Table 4 Main characteristics of included studies investigating the risk of OSA in patients with varying severity of asthma

Brinke et al. 2005 [20]

Netherlands

N = 39 (Patients with difficult-to-treat

asthma and ≥ 3 severe asthma exacerbations in the 12 months)

5

41.5 (14.1)

N/A

27.0

Cross-sectional,

AHRQ = 6

AHI ≥ 5/h

Psychopathology, chronic sinusitis, gastro-oesophageal reflux, (bacterial) respiratory infections, and obstructive sleep apnoea appear to be associated with frequent exacerbations of asthma

N = 24 (Patients with difficult-to-treat

asthma and 1 severe asthma exacerbation in 12 months)

1

Julien et al. 2009 [21]

Canada

N = 26 (Severe asthma group)

23

48.4 (1.9)

27.8 (1.2)

50.0

Cross-sectional,

AHRQ = 6

AHI ≥ 15/h

OSA is significantly more prevalent among patients with severe compared with moderate asthma, and more prevalent for both asthma groups than controls without asthma

N = 26 (Moderate asthma group)

15

Teodorescu

et al. 2012 [22]

USA

N = 283 (Patients with persistent nighttime asthma symptoms)

181

47.0 (14.0)

29.0 (7.0)

33.2

Cross-sectional,

AHRQ = 8

AHI ≥ 5/h

OSA is associated with persistent daytime asthma symptoms, to an extent that matched or exceeded associations with nighttime asthma symptoms

N = 469 (Patients without persistent nighttime asthma symptoms)

194

Byun et al. 2013 [23]

Korea

N = 44 (Moderate to severe group)

37

58.8 (12.0)

25.3 (3.8)

58.5

Cross-sectional,

AHRQ = 7

AHI ≥ 5/h

Moderate to severe asthma showed a strong correlation with OSA (AHI ≥ 5/h)

N = 21 (Control group)

3

Zidan et al. 2015 [10]

Egypt

N = 8 (Uncontrolled asthma)

6

50.2 (8.4)

27.4 (4.4)

43.3

Cross-sectional,

AHRQ = 5

AHI ≥ 5/h

A suspicion is warranted for the overlap of OSA and asthma, particularly in patients with severe asthma

N = 15 (Partly controlled asthma)

11

Wang et al. 2016 [24]

China

N = 59 (Patients occurred severe asthma exacerbations over 1 year)

24

46.7 (7.3)

24.1 (4.8)

69.9

Cohort study,

NOS = 7

AHI ≥ 5/h

The patients with asthma had a high risk of OSA, which was an

important factor associated with severe asthma exacerbations

N = 87 (Patients did not occur severe asthma exacerbations over 1 year)

4

Shaker et al. 2017 [13]

Egypt

N = 18 (Patients with severe persistent asthma)

10

44.9 (10.3)

N/A

44.0

Cohort study,

NOS = 5

AHI ≥ 5/h

There is a bidirectional relationship between OSA and asthma with increasing frequency of OSA with the increasing asthma severity

N = 21 (Patients with moderate persistent asthma)

2

Lu et al. 2017 [14]

China

N = 8 (Severe asthma group)

6

47.6 (12.1)

26.4 (3.0)

57.7

Cross-sectional,

AHRQ = 7

AHI ≥ 5/h

STOP-Bang questionnaire is a preferable sleep questionnaire better than the Berlin questionnaire for detecting moderate and severe OSA in asthmatic patients

N = 54 (Moderate asthma group)

37

Yen et al. 2017 [15]

Vietnam

N = 44 (Uncontrolled asthma)

30

9.5 (2.1)

17.4 (2.8)

72.8

Cross-sectional,

AHRQ = 7

Children ≤ 12 years: AHI ≥ 1/h, children > 12 years: AHI ≥ 5/h

The presence of allergic rhinitis, snoring, and apnea during sleep in asthmatic children is associated with a higher risk of OSA

N = 25 (Partly controlled asthma)

16

Megersa et al. 2022 [25]

Ethiopia

N = 100 (Patients occurred severe asthma exacerbations over 1 year)

47

44.3 (12.1)

N/A

38.5

Cohort study,

NOS = 6

N/A

Upper respiratory tract infection, obstructive sleep apnea, passive smoker, spring season, kitchen smoke, pet

ownership, rhinitis, and being jobless were identified as significant determinants of an asthma attack

N = 200 (Patients did not occur severe asthma exacerbations over 1 year)

27

Saif M et al. 2022 [26]

Oman

N = 163 (Uncontrolled asthma)

69

56.6 (12.4)

40.3 (12.2)

N/A

Cross-sectional,

AHRQ = 8

AHI ≥ 5/h

The risk of OSA was high (32.37%) in patients with severe asthma

Uncontrolled severe asthma was significantly associated with severe OSA

N = 135 (Controlled asthma)

32